Electrical Interference from an Abdominal Muscle Stimulator Unit on an Implantable Cardioverter Defibrillator:

Abstract

Two consecutive cases are presented of patients with ICDs in whom the use of commercial units for muscle stimulation for abdominal training caused interference with the device, mimicked cardiac signals, and resulted in inappropriate treatment shock delivery.

Neuromuscular electrical stimulation of the thighs in cardiac patients with implantable cardioverter defibrillators

“…reported on two male patients with pectoral implanted ICDs (Ventak Mini III® and Ventak AV III DR®) and neuromuscular stimulation of abdominal muscles [33]. In both patients, NMES using commercial units (5.0–11.0 V, 7.3–10 mA, 55–75 Hz/biphasic) provoked EMI, resulting in ICD discharge due to misinterpreting electrical signals as cardiac signals in the ventricular fibrillation (VF) zone (Table 1; [33]).…”

“… Home therapy (NMES) of thighs : no EMIWayar et al. 2003 [33]Case report ( n  = 2)1st patient: pectoral ICD (Ventak®  Mini III [Guidant Inc., St. Paul, Minnesota, USA])NMES of abdominal muscles55–75 Hz, biphasic, 7.3–10 mA, 5–11 VEMI in both patients2nd patient: pectoral ICD (Ventak® AV [Guidant Inc., St. Paul, Minnesota, USA]) ICD  implantable cardioverter defibrillator, NMES  neuromuscular electrical stimulation, stim  stimulation, EMI  electromagnetic interference, IG50  Impulse galvanization, dir. cur.…”

“…In contrast, inappropriate electrode positioning for NMES can provoke disturbances of ICDs [33]. In one study, 2 patients autonomously applied the stimulation too close to the implantation site of the pectoral ICD, namely to the abdominal musculature, causing discharge of the ICD by signals in the VF zone [33].…”

“…In one study, 2 patients autonomously applied the stimulation too close to the implantation site of the pectoral ICD, namely to the abdominal musculature, causing discharge of the ICD by signals in the VF zone [33]. Nevertheless, at that time, ICD programming had usually been very strict, e. g., short detection of VF and shock delivery at the first stage in the VF zone.…”

Appropriate Result from an Inappropriate ICD Shock

“…[1][2][3] The majority of these shocks (>80%) stem from nonsustained VTs or supraventricular tachycardias. Electromagnetic interference accounts for a minority of inappropriate shocks (<5%) and has been shown to arise from normally [4][5][6][7][8] and abnormally 9-12 functioning electrical appliances.…”